JP2003068588A - Structure of surface mounting solid electrolytic capacitor with safety fuse and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small and lightweight surface mounting solid electrolytic capacitor equipped with a safety fuse against overcurrent or temperature. SOLUTION: The surface mounting solid electrolytic capacitor comprises a capacitor element 2, an insulator sheet piece 3 having upper surface arranged with the capacitor element, and a package body 4 for hermetically sealing the capacitor element on the upper surface of the sheet piece. An anode terminal electrode film 5a is formed on the lower surface of the sheet piece along with a cathode terminal electrode film 6a conducting electrically with the cathode 2b of the capacitor element. Between the upper surface of the sheet piece and an anode rod 2a in the capacitor element, a safety fuse wire 7 for conducting the anode rod and the anode terminal electrode film electrically is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a solid electrolytic capacitor such as a tantalum solid electrolytic capacitor which is provided with a safety fuse against overcurrent or temperature and can be surface-mounted by soldering to a printed circuit board or the like. The present invention relates to the structure of the solid electrolytic capacitor and the manufacturing method thereof.

[0002]

2. Description of the Related Art A solid electrolytic capacitor with a safety fuse of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 6-20891, and as shown in FIG. 13, anode leads made of metal plates arranged linearly. The capacitor element 2 is disposed between the terminal 25 and the cathode lead terminal 26, and the anode rod 2a protruding from one end of the capacitor element 2 is fixed to the anode lead terminal 25 by welding or the like, while the capacitor The cathode film 2b of the element 2 and the cathode lead terminal 16 are electrically connected by a safety fuse wire 27, and the capacitor element 2 and the safety fuse wire 27 are entirely made of a synthetic resin package body. 24, the lead terminals 25 and 26 are hermetically sealed so as to project from the left and right end surfaces of the package body 24, and then the lead terminals 25 and 26 are sealed.
By bending 26 on the bottom surface side of the package body 24, it can be surface-mounted by soldering to a printed circuit board or the like.

[0003]

However, in the above-mentioned conventional solid electrolytic capacitor with safety fuse, the capacitor element 2 is arranged between the anode lead terminal 25 and the cathode lead terminal 26, which are arranged in a straight line, and the anode rod thereof. 2a is fixed to the anode lead terminal 25, and the cathode film 2b is fixed to the cathode lead terminal 2
6 has a structure in which it is electrically connected via a safety fuse wire 27, and both lead terminals 25 and 26, the capacitor element 2 and the safety fuse wire 27 are arranged in series. In addition to the fact that the safety fuse wire 27 protrudes from the upper surface of the capacitor element 2, the total length dimension L is significantly increased. Since the package 24 is bent to the bottom side, the height dimension H
As a result, the length L and the height H become large, resulting in a problem that the size cannot be reduced.

In addition, both lead terminals 25, 2 made of a metal plate
6 is projected from both left and right side surfaces of the package body 24, and both lead terminals 25 and 26 are bent to the bottom surface side of the package body 24 so that they can be surface-mounted by soldering to a printed circuit board or the like. Since two lead terminals made of a long metal plate are required, there is a problem that not only the weight increases but also the manufacturing cost increases significantly.

It is a technical object of the present invention to provide a structure of a solid electrolytic capacitor which solves this problem, and a method capable of mass-producing this solid electrolytic capacitor.

[0006]

In order to achieve this technical object, claim 1 of the present invention relates to the first structure, "a capacitor element having an anode rod protruding from one end face and this capacitor element on the upper surface. A sheet piece made of an insulator provided and a package body made of synthetic resin for sealing the capacitor element on the upper surface of the sheet piece, and an anode terminal electrode film is formed on the lower surface of the sheet piece,
While forming a cathode terminal electrode film electrically connected to the cathode of the capacitor element, the upper surface of the sheet piece,
A safety fuse wire was provided between the anode rod in the capacitor element and the anode rod to electrically connect the anode terminal electrode film. It is characterized by

Further, the second aspect of the present invention relates to the second structure, "a capacitor element having an anode rod protruding from one end face, and an anode lead terminal and a cathode made of a metal plate on which the capacitor element is arranged. The cathode lead comprises a lead terminal and a package body made of synthetic resin that seals the capacitor element on the upper surfaces of the anode lead terminal and the cathode lead terminal so that the lower surfaces of the anode lead terminal and the cathode lead terminal are exposed. While electrically connecting the terminal to the cathode of the capacitor element, between the upper surface of the anode lead terminal and the anode rod of the capacitor element,
A safety fuse wire was provided to electrically connect between them. "
It is characterized by that.

Next, a fourth aspect of the present invention relates to the manufacture of the solid electrolytic capacitor having the first structure, wherein "an anode terminal electrode film and an anode terminal electrode film forming one solid electrolytic capacitor on the lower surface of an insulating sheet material are provided. Forming a plurality of cathode terminal electrode films side by side, and forming a plurality of anode electrode films electrically conducting to each of the anode terminal electrode films on the upper surface of the sheet material, and each of the cathode terminal electrode films. A step of forming a plurality of cathode electrode films electrically connected to the sheet material, a step of electrically charging a safety fuse wire to a portion of each anode electrode film on the upper surface of the sheet material, and the sheet material. A plurality of capacitor elements are mounted on the upper surface of the capacitor element so that the anode rod of the capacitor element is electrically connected to the safety fuse wire and the cathode of the capacitor element is electrically connected to the cathode electrode film. And a step of forming a synthetic resin plate on the upper surface of the sheet material to a thickness that fills each capacitor element, and then cutting each solid electrolytic capacitor along the vertical and horizontal cutting lines between the capacitor elements. It consists of a process. "

A fifth aspect of the present invention relates to the production of the solid electrolytic capacitor having the second structure, wherein "a metal formed by arranging a plurality of anode lead terminals and cathode lead terminals forming one solid electrolytic capacitor side by side. A step of preparing a plate lead frame; a step of electrically loading a safety fuse wire to each anode lead terminal portion of the lead frame; and a plurality of capacitor elements on the upper surface of the lead frame. The step of mounting the anode rod in the capacitor element on the safety fuse wire so that the cathode in the capacitor element is electrically connected to the cathode lead terminal, and a synthetic resin plate on the upper surface of the lead frame for each capacitor element. Process to form a thickness that fills the capacitor, and then along the vertical and horizontal cutting lines between the capacitor elements. Te and a step of cutting each solid electrolytic capacitor. "Is characterized by.

[0010]

According to the structure of the first aspect of the present invention, the sheet piece can be surface-mounted by soldering to the printed board or the like by the anode terminal electrode film and the cathode terminal electrode film on the lower surface of the sheet piece. , Safety fuse wire,
By providing the sheet between the sheet piece and the anode rod of the capacitor element, it is possible to prevent the safety fuse wire from being added to the length dimension of the solid electrolytic capacitor, and to improve the height dimension of the solid electrolytic capacitor. The increase due to the safety fuse wire can also be avoided.

Further, in the structure of the second aspect, the anode lead terminal and the cathode lead terminal exposed on the lower surface of the package can be surface-mounted by soldering to a printed circuit board or the like, but are safe. By providing the fuse wire between the anode lead terminal and the anode rod of the capacitor element, it is possible to prevent the safety fuse wire from being added to the length dimension of the solid electrolytic capacitor, and It is also possible to avoid increasing the height dimension due to this safety fuse wire. Moreover, since the anode lead terminal and the cathode lead terminal do not project from the package body and are not bent to the bottom side of the package body, the length dimension and height dimension of the solid electrolytic capacitor are further reduced by this amount. it can.

Therefore, according to the present invention, in the surface mount type solid electrolytic capacitor provided with the safety fuse, the volume efficiency of the capacitor element with respect to the whole can be made high, and the overall size can be made smaller than the volume of the capacitor element. In addition to being able to do so, it has the effect of reducing the weight.

In particular, when at least one end of the safety fuse wire is exposed to the surface of the package body as described in claim 3, the safety fuse wire is melted due to overcurrent or temperature rise. Since it will flow out of the package promptly and a cavity will be created in this safety fuse wire part, not only will it function reliably and quickly and accurately as a safety fuse, but also that the safety fuse has worked. It can be easily detected from the outside.

Further, according to the manufacturing method described in claims 4 and 5, there is an effect that the surface mount type solid electrolytic capacitor with a safety fuse having the above-described effect can be manufactured at a low cost by a mass production method.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show a solid electrolytic capacitor according to the first embodiment.

The solid electrolytic capacitor 1 according to the first embodiment is made of a capacitor element 2 having an anode rod 2a protruding from one end surface and an insulator such as a synthetic resin formed to a size capable of mounting the capacitor element 2. 2 and a package body 4 made of synthetic resin such as epoxy resin for sealing the entire capacitor element 2.

On the lower surface of the sheet piece 3, an anode terminal electrode film 5a is provided at one end and a cathode terminal electrode film 6 is provided at the other end.
a is formed on the upper surface of the sheet piece 3, and the anode terminal electrode film 5 is formed on the upper surface of the sheet piece 3 through a through hole 5b.
An anode electrode film 5c electrically connected to a is formed, and a cathode terminal electrode film 6c electrically connected to the cathode terminal electrode film 6a is formed at the other end through a through hole 6b.

The capacitor element 2 is provided on the upper surface side of the sheet piece 3, and the cathode film 2b of the capacitor element 2 is provided.
Is mounted so as to contact the cathode electrode film 6c, and the cathode film 2b is electrically connected to the cathode electrode film 6c by applying a conductive paste or the like.

Further, a safety fuse wire 7 for overcurrent or temperature is arranged between the upper surface of the sheet piece 3 and the anode rod 2a of the capacitor element 2, and the safety fuse wire 7 is connected to the sheet. Anode electrode film 5c on piece 3
To the safety fuse wire 7 by electrically applying a conductive paste or soldering to the anode rod 2a of the capacitor element 2 to electrically connect the conductive fuse to the safety fuse wire 7. Connecting.

On the upper surface side of the sheet piece 3, the package body 4 for sealing the entire capacitor element 2 is formed. In this case, both ends or one end of the safety fuse wire 7 is connected to the package body 4. It is configured to be exposed on the surface of.

The solid electrolytic capacitor 1 having this structure can be surface-mounted by soldering on a printed circuit board or the like by the anode terminal electrode film 5a and the cathode terminal electrode film 6a on the lower surface of the sheet piece 3. By providing the safety fuse wire 7 between the sheet piece 3 and the anode rod 2a of the capacitor element 2, the safety fuse wire 7 is provided.
Can be prevented from being added to the length dimension L in the solid electrolytic capacitor 1, and the solid electrolytic capacitor 1
It is also possible to avoid increasing the height dimension H at H due to this safety fuse wire 7.

Further, since at least one end of the safety fuse wire 7 is exposed on the surface of the package body 4, when the safety fuse wire 7 is melted due to overcurrent or temperature rise, the outside of the package body 4 is exposed. The safety fuse wire 7 will have a cavity in it, so that not only does it function as a safety fuse reliably and quickly and accurately, but it is also easy to confirm that the safety fuse has worked from the outside. Can be detected.

3 and 4 show a solid electrolytic capacitor according to the second embodiment.

The solid electrolytic capacitor 11 according to the second embodiment includes a capacitor element 2 having an anode rod 2a protruding from one end face thereof, a pair of metal plate anode lead terminals 15 and cathode lead terminals 16, and the capacitor described above. It is configured by a package body 14 made of synthetic resin such as epoxy resin for sealing the entire element 2.

The capacitor element 2 is mounted on the upper surfaces of the lead terminals 15 and 16 so that the cathode film 2b of the capacitor element 2 contacts the cathode lead terminal 16, and the cathode film 2b is mounted on the cathode lead. The terminal 16 is electrically connected by applying a conductive paste or the like.

The upper surface of the anode lead terminal 15 and
A safety fuse wire 17 for overcurrent or temperature is arranged between the anode rod 2a of the capacitor element 2 and
The safety fuse wire 17 is electrically connected to the anode lead terminal 15 by applying a conductive paste, soldering, or the like, and further, the safety fuse wire 17 is connected to the anode rod 2a of the capacitor element 2. Are electrically connected by applying a conductive paste or the like.

The package body 14 for sealing the entire capacitor element 2 is exposed on the upper surface side of the lead terminals 15, 16 and the lower surfaces of the lead terminals 15, 16 are exposed on the bottom surface of the package body 14. In this case, both ends or one end of the safety fuse wire 17 is exposed to the surface of the package body 14.

The solid electrolytic capacitor 11 having this structure can be surface-mounted by soldering to a printed circuit board or the like by the anode lead terminal 15 and the cathode lead terminal 16 exposed on the lower surface of the package body 14. ,
By providing the safety fuse wire 17 between the anode lead terminal 15 and the anode rod 2a of the capacitor element 2,
The safety fuse wire 17 can be prevented from being added to the length dimension L of the solid electrolytic capacitor 11, and the height dimension H of the solid electrolytic capacitor 11 can be prevented from increasing due to the safety fuse wire 17. it can. Moreover, since the anode lead terminal 15 and the cathode lead terminal 16 do not project from the package body 14 and are not bent to the bottom surface side of the package body 14, the length dimension L and the height of the solid electrolytic capacitor are increased accordingly. Size H
Can be further reduced.

Next, FIGS. 5 to 10 show the above-mentioned FIGS.
A first method of manufacturing the solid electrolytic capacitor 1 according to the first embodiment shown in FIG.

In the first manufacturing method, first, as shown in FIGS. 5 and 6, a sheet material A made of an insulating material such as synthetic resin is prepared, and one solid electric field is formed on the upper surface of the sheet material A. Anode electrode film 5c and cathode electrode film 6c constituting the capacitor 1
A plurality of anode terminal electrode films 5a electrically connected to the anode electrode film 5c through the through holes 5b and a cathode electrode film 6c are formed on the lower surface of the sheet material A. A plurality of cathode terminal electrode films 6a electrically connected through the through holes 6b are formed.

Next, as shown in FIGS. 7 and 8, a safety fuse wire 7 is extended in the column direction of each anode electrode film 5c at the portion of each anode electrode film 5c on the upper surface of the sheet material A. After arranging as described above, the safety fuse wire 7 is electrically connected to each of the anode electrode films 5c by soldering or applying a conductive paste.

Next, as shown in FIG. 9, a plurality of capacitor elements 2 each having an anode rod 2a protruding from one end surface are provided on the upper surface of the sheet material A, and the anode rod 2a in the capacitor element 2 has the safety fuse wire. 7, the cathode 2b of the capacitor element 2 is mounted so as to be in contact with the cathode electrode film 6c, and then the anode rod 2a is attached to the safety fuse wire 7
While electrically connected by applying a conductive paste to the
The cathode 2b is electrically connected to the cathode electrode film 6c by applying a conductive paste or the like.

Then, as shown in FIG. 10, a frame (not shown) surrounding the sheet material A is placed on the upper surface of the sheet A, and a heat resistant synthetic resin such as an epoxy resin in a liquid state is placed in the frame. The synthetic resin plate B constituting the package body 4 for sealing the entire capacitor elements 2 is formed by pouring to a depth at which the capacitor elements 2 are completely immersed and then hardening.

Next, the sheet material A and the synthetic resin plate B
Are cut along a vertical cutting line C1 and a horizontal cutting line C2 by a dicing cutter into a plurality of solid electrolytic capacitors 1.

As a result, a plurality of solid electrolytic capacitors 1 having the structure shown in FIGS.
Can be manufactured at the same time.

FIGS. 11 and 12 show a second method for manufacturing the solid electrolytic capacitor 11 according to the second embodiment shown in FIGS. 3 and 4.

In the second manufacturing method, first, as shown in FIG. 11, a lead frame D made of one thin metal plate is prepared, and the lead frame D is punched out.
A plurality of anode lead terminals 15 and cathode lead terminals 16 that constitute one solid electrolytic capacitor 11 are formed side by side.

Next, as shown in FIG. 12, each of the anode lead terminals 1 on the upper surface of the lead frame D.
The safety fuse wires 17 are arranged at the portion 5 so as to extend in the column direction in each anode lead terminal 15, and then the safety fuse wires 17 are soldered or conductive paste to each anode lead terminal 15. It is electrically connected by coating.

Then, in the same manner as in the first manufacturing method, the capacitor element 2 is formed on the upper surface of the lead frame D.
A plurality of positive electrode rods 2a in the capacitor element 2
Is mounted on the safety fuse wire 17 so that the cathode 2b of the capacitor element 2 is in contact with the cathode lead terminal 16 respectively, and then the anode rod 2a is mounted on the safety fuse wire 17.
While electrically connected by applying a conductive paste to the
The cathode 2b is electrically connected to the cathode lead terminal 16 by applying a conductive paste or the like.

Then, on the upper surface of the lead frame D,
By placing a frame body (not shown) surrounding the periphery of the frame body and pouring the heat resistant synthetic resin such as an epoxy resin in a liquid state to a depth at which the capacitor elements 2 are completely immersed, and then curing, A synthetic resin plate forming a package body 14 for sealing the whole of each capacitor element 2 is formed.

Then, the lead frame D and the synthetic resin plate are cut along the cutting lines E1, E2, E3, E4 in the vertical direction and the cutting lines F in the horizontal direction with a dicing cutter.
The plurality of solid electrolytic capacitors 11 are cut.

As a result, a plurality of solid electrolytic capacitors 11 having the structure shown in FIGS. 3 and 4 can be manufactured simultaneously from one lead frame D.

The vertical cutting lines E1, E2,
When cutting along E3, E4, the part of the width W between the cutting lines E2, E3 among the cutting lines E1, E2, E3, E4 is cut by cutting with a wide dicing cutter. Is preferable because of its low cost.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a solid electrolytic capacitor according to a first embodiment of the present invention.

FIG. 2 is a sectional plan view taken along the line II-II of FIG.

FIG. 3 is a vertical sectional front view of a solid electrolytic capacitor according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along the line IV-IV of FIG.

FIG. 5 is a perspective view showing a sheet material used for manufacturing the solid electrolytic capacitor according to the first embodiment.

6 is an enlarged sectional view taken along line VI-VI of FIG.

FIG. 7 is a perspective view showing a state in which a safety fuse wire is attached to the sheet material.

8 is an enlarged sectional view taken along line VIII-VIII of FIG. 7.

FIG. 9 is an enlarged cross-sectional view showing a state in which a capacitor element is mounted on the sheet material.

FIG. 10 is an enlarged cross-sectional view showing a state in which a synthetic resin plate for sealing a capacitor element is formed on the sheet material.

FIG. 11 is a perspective view showing a lead frame used for manufacturing the solid electrolytic capacitor according to the first embodiment.

FIG. 12 is a perspective view showing a state in which a safety fuse wire is attached to the lead frame.

FIG. 13 is a vertical sectional front view showing a conventional individual plate electrolytic capacitor.

[Explanation of symbols]

1,11 Solid electrolytic capacitor 2 Capacitor element 2a Anode rod of capacitor element 2b Capacitor cathode 3 sheet pieces 4,14 package 5a Anode terminal electrode film 6a Cathode terminal electrode film 15 Anode lead terminal 16 Cathode lead terminal 7,17 Safety fuse wire A sheet material D lead frame

Claims (5)

[Claims] 1. A capacitor element having an anode rod protruding from one end surface, an insulating sheet piece having the capacitor element disposed on the upper surface, and a synthetic resin member for sealing the capacitor element on the upper surface of the sheet piece. And a cathode terminal electrode film that is electrically connected to the cathode of the capacitor element, while forming an anode terminal electrode film on the lower surface of the sheet piece, and an upper surface of the sheet piece, and A structure of a surface mount type solid electrolytic capacitor with a safety fuse, characterized in that a safety fuse wire for electrically conducting the anode rod and the anode terminal electrode film is provided between the anode rod in the capacitor element. 2. A capacitor element having an anode rod protruding from one end surface, an anode lead terminal and a cathode lead terminal made of a metal plate, the capacitor element being disposed on the upper surface, and upper surface sides of the anode lead terminal and the cathode lead terminal. In the package element made of synthetic resin for sealing the capacitor element so that the lower surfaces of the anode lead terminal and the cathode lead terminal are exposed, while electrically connecting the cathode lead terminal to the cathode of the capacitor element, A structure of a surface mount type solid electrolytic capacitor with a safety fuse, wherein a safety fuse wire is provided between the upper surface of the anode lead terminal and the anode rod of the capacitor element so as to electrically connect between them. 3. The structure of a surface mount type solid electrolytic capacitor with a safety fuse according to claim 1 or 2, wherein at least one end of the safety fuse wire is exposed on a surface of the package body. 4. A step of forming a plurality of anode terminal electrode films and cathode terminal electrode films constituting one solid electrolytic capacitor side by side on the lower surface of an insulating sheet material, and the anode terminal on the upper surface of the sheet material. Forming a plurality of anode electrode films electrically connected to each of the electrode films and forming a plurality of cathode electrode films electrically connected to each of the cathode terminal electrode films; and an upper surface of the sheet material. A step of loading a safety fuse wire on each of the anode electrode films so as to be electrically conducted, and a plurality of capacitor elements on the upper surface of the sheet material, the anode rod in the capacitor element being the safety fuse wire, The step of loading the cathode of the capacitor element so that the cathode electrode film is electrically connected to each other, and the thickness of the synthetic resin plate on the upper surface of the sheet material to fill each capacitor element are formed. Process and method of manufacturing a safety fuse with surface mount solid electrolytic capacitor characterized in that comprising a step of cutting along the vertical and horizontal cut lines for each solid electrolytic capacitor between the capacitor elements in subsequent to. 5. A step of preparing a lead frame made of a metal plate, which is formed by arranging a plurality of anode lead terminals and cathode lead terminals forming one solid electrolytic capacitor side by side, and a step of preparing each lead lead terminal in the lead frame. A step of electrically loading a safety fuse wire, and a plurality of capacitor elements on the upper surface of the lead frame, the anode rod of the capacitor element being the safety fuse wire, and the cathode of the capacitor element being the cathode lead. A step of loading the terminals so that they are electrically connected to each other, a step of forming a synthetic resin plate on the upper surface of the lead frame so as to fill each capacitor element, and then a vertical and horizontal cutting line between each capacitor element. And a process of cutting each solid electrolytic capacitor along with Method of manufacturing's with surface mount solid electrolytic capacitor.